package com.lxk.util;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * 向工具类中注入spring容器中的内容，如mapper,service
 * @author JohnSoybean
 * @time 2020年3月13日
 */
@Component
public class SpringContextHolder implements ApplicationContextAware {

	private static ApplicationContext applicationContext;
	
	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		SpringContextHolder.applicationContext = applicationContext;
	}
	
	public static void setContext(ApplicationContext applicationContext) {
		if (SpringContextHolder.applicationContext == null) {
			SpringContextHolder.applicationContext = applicationContext;
		}
	}
	
	public static ApplicationContext getApplicationContext() {
		assertApplicationContext();
		return applicationContext;
	}
	
	@SuppressWarnings("unchecked")
	public static <T> T getBean(String beanName) {
		assertApplicationContext();
		return (T) applicationContext.getBean(beanName);
	}
	
	public static <T> T getBean(Class<T> requiredType) {
		assertApplicationContext();
		return applicationContext.getBean(requiredType);
	}
	
	private static void assertApplicationContext() {
		if (SpringContextHolder.applicationContext == null) {
			throw new RuntimeException("applicaitonContext属性为null,请检查是否注入了SpringContextHolder!");
		}
	}

}
